Battery Amp Hour

jffnkrn wrote:
Does the amp hour rating double when two twelve volt batteries are used? I understand that they need to be both new so they don't go down to the lowest setting. thanks

There you go assuming all 12 volt batteries are the same size.

This "12 volt battery" without any reference to size is one of my pet peaves cause I have used 12 olt batteries ranging in capacity from a handful of amp hours (like 5 To well over 1000,

IF you parallel two 12 volt batteries OF THE SAME SIZE yes it doubles

If they are different sizes, it adds (Actually in all cases it adds).


You may stop reading here.


By the same measure if you put two identical batteries in series the VOLTAGE adds (Doubles in this case) if thy are NOT identical bad things happen and you get all messed up. But this only applis to this side of that You may stop line.

Actually you get a little more than double due to the Peukert effect.
Effectively cutting discharge for each in half makes both together more efficient.
Or put "Peukert" into wiki.

If you can get deep cycle batteries, you're golden.
Trojan is the industry standard for 6V batteries. I bought 2-Sam's Club 6V's, out the door for $190, including the core charge. They are working well.

Good info for me as well. I would like to add I was using the T-105 Trojans, good batteries. The owner before me was not that experienced in care of batteries. I finally switched them out. Went to Napa and replaced with exact size and voltage. Batteries cost $350 and tax. A warranty of 72 months, with a 36 month total replacement if they go bad. Just some info for you as to finding your Batts locally or interstate rout. BTW I did purchase an interstate for the Ford V-10, that thing is brute. Next 105's I get will prob be interstate.

Well with the led lighting in the new unit and having a generator and solar available, I believe I am going to bite the bullet and spend $350 for the GPL-31T or $420 for a GPL-31XT. The GPL-31XT has 125 amp hours. We have always been good with 2 standard group 29 or 30 batteries with a total of 200 amp hours and regular lighting. So that's my story and I am sticking to it. Any other input is welcome. I won't be making the purchase until late week, need a few xtra $$$.

The amp hour is a unit of charge (3600 Coulombs), not energy. The volt amp hour = watt hour is a unit of energy. A 100 amp hour 12 volt battery stores 12x100 = 1200 watt hours or 1.2 kilowatt hours. A 200 amp hour 6 volt battery stores 1.2 kWh as well. About 20 cents worth from the power company.

so two group 27 batteries will give you about 200 ah. probably will go that route again. had them in the trailer, and now have a fifth wheel, more area to heat, more lights, but LED and should be good to go. have generator also. thanks all. have a great day, happy traveling, camping etc. Good luck & Be Safe ! ! !

If you have 2 6V batteries and one goes bad you only 1 6V battery and that won't power anything in the trailer. Probably won't happen very often but something to consider. 6V batteries are larger also so make sure you have enough room if you go that route.

Terminology is incorrect, nothing doubles, it is added.

Example;
one 12v group 24 @ 80ah
one 12v group 27 @ 100ah

What exactly do you double? You don't, you add.

jffnkrn wrote:
Does the amp hour rating double when two twelve volt batteries are used? I understand that they need to be both new so they don't go down to the lowest setting. thanks

Assuming all batteries are identical

If you put two 12 volt in parallel, yes the amp hours double

IF you put two six volt in series the VOLTAGE doubles

IF batteries are NOT identical

Two 12 volt in parallel. you add the amp hours together

Example a 4D (230 amp hours) and a Group 31 (130) = 360 amp hours

Two six volt non-identical in series is NOT RECOMMENDED and will not work well.